As Moore's Law advances into a 22-nm technology node, a traditional planar field-effect transistor cannot meet a requirement of low power consumption and high performance. To overcome a short-channel effect and increase a density of driving current in a unit area, a large-scale integrated circuit manufacturing technology is introduced to a fin field-effect transistor (Fin Field-Effect Transistor; Fin FET) having a three-dimensional structure. Due to a larger gate control area and a narrower channel depletion zone, this structure has a very outstanding short-channel control capability and very high driving current.
A Fin FET is an emerging structure. The structure includes a narrow and independent fin, where gates are on two sides of the fin. An advantage lies in that gates of a channel may be controlled from the two sides, so that a device is smaller, and has higher performance and lower power consumption. The fin in the Fin FET includes a source zone and a drain zone, and an active zone of the fin is segmented by means of shallow trench isolation (STI). The Fin FET further includes a gate zone located between the source zone and the drain zone. The gate zone is formed on an upper surface and side walls of the fin, so that the gate zone wraps and surrounds the fin. A part, extending under the gate and located between the source zone and the drain zone, of the fin is a channel zone.
In the prior art, a fin in a Fin FET device is generally fabricated by using a photoetching technology. However, the fin fabricated by using the photoetching technology has a rough side surface, and the fin cannot be perpendicular to a surface of a substrate.